Probing the nature of Z_c states via the eta_c rho decay

Understand

The nature of the so-called XYZ states is a long-standing problem.

• It has been suggested that such particles may be described as compact four-quark states or loosely bound meson molecules.
• In the present work we analyze the Z_c(') -> eta_c rho decay using both approaches.
• Such channel might provide useful insights on the nature of the Z_c('), helping discriminating between the two different models.